Window treatment accessory



FIG. 1 is an environmental perspective view of the claimed window treatment accessory with the broken line showing of fragmented curtain pole, curtain and holder being for illustrative purposes only and forms no part of the claimed design;

FIG. 2 is a top plan view thereof the bottom plan view being a mirror image of the top plan view;

FIG. 3 is a front view thereof the rear view being a mirror image of the front view;

FIG. 4 is a right side view thereof; and,

FIG. 5 is a left side view thereof. 

The ornamental design for a window treatment accessory, as shown and described in the drawings. 